Remove getNodesInCommand debug method from Editing commands

Source/core/editing/EditCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2007 Apple, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 92 matching lines @@
         m_startingSelection = parent->m_endingSelection;
         m_endingSelection = parent->m_endingSelection;
     }
 }
 
 void SimpleEditCommand::doReapply()
 {
     doApply();
 }
 
-#ifndef NDEBUG
-void SimpleEditCommand::addNodeAndDescendants(Node* startNode, HashSet<Node*>& nodes)
-{
-    for (Node* node = startNode; node; node = NodeTraversal::next(node, startNode))
-        nodes.add(node);
-}
-#endif
-
 } // namespace WebCore